CMSC 341 Project 4 Notes

20 Nov 2001
- New sample output files have been created in Mr. Frey's public directory. The original p4output file was renamed to p4output.64K
  Note that it is not necessary to match every value in the same output exactly. This shouldn't be a project in which you try to guess how I implemented the project. What is important is that the sample output data has certain properties that allow you to answer the project questions. If your output doesn't match exactly, it still MUST exhibit these same properties.
- Some students are still confused about the definition of "comparison", so here goes...
  Counting comparisons is a way to measure the running time of find/insert/remove/etc. By counting how many times these methods compare the data value being found/inserted/removed with the data in a node in the tree, we can measure how far down the tree find/insert/remove have traversed
  A comparison occurs when a tree method is traversing the tree, arrives at a node and must decide to (a) go left, (b) go right, or (c) stop. The code (in a BST) typically looks like This if/else if/else structure counts as one comparison. In the top-down splay tree code, it's not so obvious.
  Hope that helps
Have a good Thanksgiving
09 Nov 2001
The data file of integers will contain only non-negative values. Therefore, using -1 as ITEM_NOT_FOUND when contructing the trees will work just fine.
08 Nov 2001
As in other projects, you are not permitted to change the public interface of any classes provided for you. You may of course add any private data members or method that you feel are necessary. In this project there are two exceptions to this policy
1. It may be necessary for some const tree functions to be changed to non-const as the result of adding code to count nodes, or count comparisons, or other similar record keeping
2. Both SplayTree.H and BinarySearchTree.H declare their nodes as BinaryNode classes. This duplication is likely to cause compiler errors and/or warnings when both .H files are included in Proj4.C. Change the name of one or both of them as you like. You will also have to change all the references to the node class whose name you change within SplayTree.C and/or BinarySearchTree.C Any good editor (i.e. xemacs) will have a "global search and replace" function that let's you do this effortlessly.